PLATE XX. 
Figs. 1 , la, lb. — Cryptolaria geniculata (p. 41). 
Fig. 1. — Portion of a colony ; natural size. 
Fig. la . — Portion of same, with two gonangia ; magnified 10 diameters. 
Fig. lb . — Same after maceration in caustic potash. The axial and peripheral tubes 
separated from one another ; magnified 10 diameters. 
Figs. 2, 2a. — Cryptolaria gracilis (p. 42). 
Fig. 2. — A colony ; natural size. 
Fig. 2a. — Portion of a colony ; magnified 10 diameters. 1 
